Helicopter hook-up and static electricity grounding device

ABSTRACT

A grounded pole for attaching a load-carrying sling to a helicopter comprising: a hollow extension pole made from a nonconducting material; a hook-up head attached to one end of the pole and made from a conducting material, the head including a frame, two U-shaped members mounted on the frame and spaced from each other along a line perpendicular to the pole axis; an arcuate member mounted on the frame midway between and below the U-shaped members and extending upwardly and outwardly from the pole; a grounding cable connectable at one end to a grounding rod and connected at the other end through the lower end of the pole to a metallic plug; and a wire braid extending through the bore of the pole to connect the plug to the hook-up head so as to conduct to ground any static electricity which may be transferred from the helicopter to the hook-up head.

United States Patent Corbin 1 HELICOPTER HOOK-UP AND STATIC ELECTRICITYGROUNDING DEVICE [76] Inventor: Joseph G. Corbin, 5251 Alabama Ave.,Camp LeJeune, NC. 28542 [22] Filed: June 27, 1974 [21] Appl. No.:483,498

July 1, 1975 [57] ABSTRACT A grounded pole for attaching a load-carryingsling to a helicopter comprising: a hollow extension pole made from anonconducting material; a hook-up head attached to one end of the poleand made from a conducting material, the head including a frame, two U-shaped members mounted on the frame and spaced from each other along aline perpendicular to the pole axis; an arcuate member mounted on theframe midway between and below the U-shaped members and extendingupwardly and outwardly from the pole; a grounding cable connectable atone end to a grounding rod and connected at the other end through thelower end of the pole to a metallic plug; and a wire braid extendingthrough the bore of the pole to connect the plug to the hook-up head soas to conduct to ground any static electricity which may be transferredfrom the helicopter to the hook-up head.

10 Claims, 14 Drawing Figures 1 HELICOPTER HOOK-UP AND STATICELECTRICITY GROUNDING DEVICE STATEMENT OF GOVERNMENT INTEREST Theinvention described herein may be manufactured and used by or for theGovernment of the United States of America for governmental purposeswithout the payment of any royalities thereon or therefor.

BACKGROUND OF THE INVENTION This invention relates to the reduction orelimination of static electric shock in the external loading ofhelleopters and especially to a hand-held grounded pole device forexternally loading a hovering helicopter.

In flight, a helicopter generates and stores a charge of staticelectricity. Since the advent of helicopter ex' ternal loadingoperations, helicopter support team personnel have been subjected tosevere shock from this static electricity and the danger of beingcrushed between the aircraft and the external load during the hook-upphase of the cargo handling operation. Various wands. shepherd crooksand other devices have been utilized in an attempt to eliminate thesehazards but none have been completely satisfactory.

The method currently in use by the Armed Forces for external helicopterloading requires the ground personnel to make the hook-up to thehelicopter by hand. in this maneuver, the becket end of the sling ishooked to the aircraft lifting hook by a man who stands astride theproposed load under the hovering helicopter. This subjects the man to asevere. static electric shock and the danger of being crushed betweenthe aircraft and the external load.

Shipboard loading is even more dangerous since the loader must contendnot only with the aircrafts vertical and horizontal movements but alsowith the movement of the ship. This, coupled with the static electricshock, makes the hand hookup method of loading even more hazardous.Thus, a definite need exists for a device which eliminates or reducesthe danger of electric shock.

SUMMARY OF THE INVENTION The invention comprises a pole-like devicehaving means for holding a donut to which the becket ends of aload-carrying sling are attached. The donut can be raised by thepole-like device and placed over a hook carried on the bottom of ahovering helicopter. The device includes means for grounding the staticelectricity charge of the helicopter without allowing the man holdingthe device to be shocked.

OBJECTS OF THE INVENTION An object of this invention is to eliminate thedanger of static electric shock to a man who is externally loading ahovering helicopter.

Another object is to provide a safe, rapid method of hooking-up externalloads to a hovering helicopter.

Another object is to provide a man who is externally loading a hoveringhelicopter with a safe distance between the aircraft and the load.

A further object is to permit a man who is loading a hovering helicopterto do so from the ground plane rather than from the top of the loaditself.

Other objects, advantages. and novel features of the present inventionwill become apparent from the following detailed description of theinvention when con- 2 sidered in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE FIGURES FIG. I is a front view, partiallybroken away, of an embodiment of the invention.

FIG. 2 is a side view, partially broken away, of the same embodiment.

FIGS. 3A. 3B, and 3C are a front. side and rear view. respectively. ofthe hook-up head.

FIG. 4A is a front view of a grip.

FIG. 4B is a side view of the outer side of a grip.

FIG. 4C is a front view of the back of a grip.

FIG. 4D is a side view of the inner side of a grip.

FIG. 5 is a view of the bottom ofthe pole showing the slot cut throughthe pole to expose the side hold in the bottom plug.

FIG. 6 is a view of the bottom plug.

FIG. 7 is a cut-away view through the pole.

FIG. 8 is a view of the bottom ofthe pole showing the sleeve, shieldsand clamps.

FIG. 9 is a perspective view of a man using the invention.

DETAILED DESCRIPTION OF THE INVENTION A grounding/sling attacher devicemade according to the present invention is shown in FIG. I. In thisfront view, a hook-up head 10 is attached at the upper end of a pole 12.An electrical cable 14 is attached at one end to a clamp 16 which isattached to a metallic grounding rod 18, for example, a brass rod. whichis inserted in the ground 20. At its other end. the cables centerconductor is attached to a plug in the pole I2. as will be describedlater.

The pole 20 is typically about 5 feet 3 inches long. with a l-inch ID.and is a hollow tube, preferably of fiberglass, although anystructurally strong, rigid, nonconductive material could be used.

The hook-up head I0 is shown in front view in FIG. I and in side view inFIG. 2. However, the details of its construction are best seen in FIGS.3A, B and C. In the front view, FIG. 3A. it can be seen that the head 10comprises an inverted triangular frame 22 having U- shaped grips 24 and24 attached at the ends of the base 26 of the triangular frame. Thesides of the triangular frame 22 are attached at the apex of thetriangle to a metallic plug 28 of cylindrical shape. The upper end ofthe plug 28 is narrowed to receive the ends of the sides of the frame 22and is slotted to receive one end of an arcuate member 30. The plug 28may be formed from a l-inch diameter piece of aluminum round stockknurled along its entire length which is about 6 inches. It has athreaded hole 32 at its lower end which is drilled and tapped for a V4 X1 inch machine screw.

The frame 22 also includes a pair of upstanding members 34 and 34' whichare substantially rectangular when viewed from the side (FIG. 3C). Thesemembers are placed in the middle of and support the U-shaped grips 34and 34'.

The dimensions of the hook-up head are typically as follows:

plug height, 6 inches;

distance from bottom of plug to uppermost tip of arcuate member. 8-V2inches;

distance from bottom of plug to top of grips, 14-5/16 inches;

distance from bottom of plug to bottom of grips. 10-5/16 inches.

distance between inner sides of grips. 4%: inches;

distance between inner sides of upstanding frame members. 5- /8 inches.

The hookup grips and the frame are constructed from i i-inch aluminumplate. The triangular frame members are 1-inch wide. The edges of theside mem bers are leveled and smoothed.

All parts of the hook-up head It) are securely attached in theconfiguration shown. preferably by welding. The plug 28 is then insertedin the upper end of the pole l2 and securely attached thereto. as bycementing with epoxy. for instance.

Another 6 inch metallic plug 42 (FIG. 6) is inserted at the bottom endof the pole [2. This plug is a straight cylinder without any narrowedsegment. It has a threaded hole 44 at the top and a threaded hole 46 inits side about Vs of the way down from the top. It. also. is knurled onthe outer surface.

A metallic braid 42 with lugs on each end is fastened to the top andbottom plugs 28 and 42, respectively. by putting screws through the endlugs and screwing the screws into the holes in the plugs. The plugs arethen cemented into place in the tube. preferably with epoxy resin (seeFIG. 7).

A slot 52 is cut through the pole 12 in such a way as to expose the hole46 in the side of the bottom plug 42 (see FIG. 5). The other end of thecable I4 is placed in the slot 52 and fastened down so that the cablecon ductor makes electrical contact with the side of the plug 42. Thiscan be done for example. by soldering a lug to the end of the cablesinner conductor and screwing the lug down over the hole 46.

A rubber sleeve 50 is now placed over the pole about two or three inchesup from the bottom. The sleeve 50 cover the cable. the cable connectionto the plug and the slot 52 in the pole 12 (see FIG. 8).

A pair of substantially semicircular shield members 54 and 54'. cut froma piece of the fiberglass pole. are placed around the rubber sleeve 50so that one covers the slot 46 and cable emerging from the slot. Theshield members are then kept in place by any suitable means. such aswater hose clamps 56 and 56' of the type used to hold radiator hoses inautomobiles.

The pair of shield members 54 and 54 may be a single shield member if apiece of tubular fiberglass with a slightly larger diameter than thatused for the pole I2 is available.

A protecting cap 58. preferably of rubber. is placed over the bottom endof the pole [2.

It is obvious. of course. that there are other ways to construct thegrounding and attachment device within the spirit of the invention. Forexample. the cable could enter the bottom of the pole and the centercable could be attached to the bottom plug by a machine screw. the plughaving a threaded hole in extending upward from its bottom surface.

Coming now to the way in which the grounding sling attacher is used. theMarine Corps. for example. in attaching loads. such as a crate 60, tothe carrying hook 62 beneath a helicopter 64, usually utilizes a netlikesling 66. The load is placed in the sling 66 and the sling straps areformed into four clusters. for example. which are looped around what isknown as a donut 68. (The donut 68 is simply a lifting ring formed froma circle of loops of a single strap held together by one or morefasteners.)

When the sling straps are coupled to the donut 68. the donut is placedin the grips 24 and 24', one side of 5 the donut in each grip. Thebottom of the donut is placed between the frame of the hookup head andthe arcuate member 30 so that it is held in by the latter.

The man 70 who is doing the loading now lifts the hook-up head by meansof the pole with the rear of the hook-up head towards him and. as thehelicopter. hov' crs above him. slips the donut over the helicopters carrying hook 62. He then pulls the head backwards. releasing the donutfrom the head. The donut stays on the hook 62 and the copter is ready torise with the load as soon as the man steps back out of the way.

If the copter is carrying a charge of static electricity. a dischargewill take place from the copter to the hookup head. The electricity willthen be grounded through the following path: hook-up; top plug; wirebraid inside the pole; bottom plug; cable; clamp; grounding rod. The man70 is protected from the static-electricity discharge since he isholding the non-conducting pole and has no contact with any of themetallic parts.

The dimensions given herein are typical. but approximate.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It is therefore to beunderstood that. within the scope of the appended claims. the inventionmay be practiced otherwise than as specifically described.

What is claimed is: l. Grounded pole means for attaching a donut to anelevated hook. said donut having straps from a loadcarrying slingcoupled to it. comprising, in combination:

a hollow pole made from electrically non-conductive material and havingtop and bottom ends;

hook-up means attached to the pole at its top end for holding said donutand placing it on said helicopter hook. said hook-up means being madefrom electrically conductive material; grounding means. attached to thepole at its bottom end, for grounding electrical discharges. and

electrical connection means forming a conductive path between saidhook-up means and said grounding means. r

2. Grounded pole means as in claim I, wherein said hook-up means is madefrom aluminum and said pole is made from fiberglass.

3. Grounded pole means as in claim I, wherein said hook-up meanscomprises:

frame means;

a pair of spaced U-shaped grips attached at the top of the frame means;and

an arcuate member attached to the frame means near the pole. saidarcuate member extending outwardly from the axis of the pole andupwardly toward the grips in the shape of a hook.

4. Grounded pole means as in claim 1, wherein said hook-up meanscomprises:

frame means substantially triangular in shape. the

base of the triangle being above the top end of the pole and the sidesof the triangle extending downwards for attachment at the pole end;

a pair of U-shaped grips. a different one attached at each end of thebase of the frame means; and

an arcuate member attached to the frame means near the pole end, saidarcuate member extending outwardly from the axis of the pole andupwardly toward the grips in the shape of a hook.

5. Grounded pole means as in claim 1, wherein said grounding meansincludes a conductive cable attached at one end to the bottom end ofsaid grounded pole means, a clamp attached to the other end of saidconductive cable, and a grounding rod for penetrating the earth. theclamp being attachable to the grounding rod.

6. Grounded pole means as in claim 4, wherein said frame means includesa first plug which fits into the top end of said pole, the apical endsof said triangular frame means and the lower end of said arcuate memberbeing attached to the plug at the end of the plug nearest the top end ofthe pole.

7. Grounded pole means as in claim 6, wherein said 6 pole is tubular andsaid plug is cylindrical in shape 8. Grounded pole means as in claim 6,further including a second conductive plug and a length of conduc tivematerial. said second plug fitting into the bottom end of said pole, theconductive cable being attached to said plug and the length ofconductive material is attached internally of said pole between saidfirst and second plugs 9. Grounded pole means as in claim 6. whereinsaid frame means. said grips, said arcuate member and said plugs arefabricated from aluminum and said pole from fiberglass.

l0. Grounded pole means as in claim 9. wherein all attachments on saidhook-up means are made by weld-

1. Grounded pole means for attaching a donut to an elevated hook, said donut having straps from a load-carrying sling coupled to it, comprising, in combination: a hollow pole made from electrically non-conductive material and having top and bottom ends; hook-up means attached to the pole at its top end for holding said donut and placing it on said helicopter hook, said hook-up means being made from electrically conductive material; grounding means, attached to the pole at its bottom end, for grounding electrical discharges; and electrical connection means forming a conductive path between said hook-up means and said grounding means.
 2. Grounded pole means as in claim 1, wherein said hook-up means is made from aluminum and said pole is made from fiberglass.
 3. Grounded pole means as in claim 1, wherein said hook-up means comprises: frame means; a pair of spaced U-shaped grips attached at the top of the frame means; and an arcuate member attached to the frame means near the pole, said arcuate member extending outwardly from the axis of the pole and upwardly toward the grips in the shape of a hook.
 4. Grounded pole means as in claim 1, wherein said hook-up means comprises: frame means substantially triangular in shape, the base of the triangle being above the top end of the pole and the sides of the triangle extending downwards for attachment at the pole end; a pair of U-shaped grips, a different one attached at each end of the base of the frame means; and an arcuate member attached to the frame means near the pole end, said arcuate member extending outwardly from the axis of the pole and upwardly toward the grips in the shape of a hook.
 5. Grounded pole means as in claim 1, wherein said grounding means includes a conductive cable attached at one end to the bottom end of said grounded pole means, a clamp attached to the other end of said conductive cable, and a grounding rod for penetrating the earth, the clamp being attachable to the grounding rod.
 6. Grounded pole means as in claim 4, wherein said frame means includes a first plug which fits into the top end of said pole, the apical ends of said triangular frame means and the lower end of said arcuate member being attached to the plug at the end of the plug nearest the top end of the pole.
 7. Grounded pole means as in claim 6, wherein said pole is tubular and said plug is cylindrical in shape.
 8. Grounded pole means as in claim 6, further including a second conductive plug and a length of conductive material, said second plug fitting into the bottom end of said pole, the conductive cable being attached to said plug and the length of conductive material is attached internally of said pole between said first and second plugs.
 9. Grounded pole means as in claim 6, wherein said frame means, said grips, said arcuate member and said plugs are fabricated from aluminum and said pole from fiberglass.
 10. Grounded pole means as in claim 9, wherein all attachments on said hook-up means are made by welding. 